Gardening Answers Knowledgebase

Is there something I can do to prevent my apple trees from getting woolly aphids? I'd rather not have to spray anything.

Answer:

Encouraging beneficial insects is one step you can take. A 2013 study at Washington State University found that planting Alyssum flowers attracted syrphids which did a good job of reducing woolly aphid populations. Here are highlights of the paper that was published based on the study's findings:

Natural enemies were found to move between sweet alyssum and adjacent apple trees.

As Washington State University's HortSense website (search under "tree fruit," "apple," then "aphids") indicates, encouraging beneficial insects is a good practice for the control of all 3 main types of aphids affecting apples, be they woolly, rosy, or green:

Control honeydew-feeding ants, which may protect aphid colonies from predators.